The present research was conducted to study effectiveness of unified trans diagnostic treatment on brain-behavioral systems and anxiety sensitivity in female students with social anxiety symptoms. The statistical population of this study included all undergraduate female students of Ahvaz Jundishapur University of medical sciences. In a pre-posttest experimental design with control group, 32 female students with the diagnosis of social anxiety disorder were selected by cluster random sampling. Then, all of the subjects were randomly allocated & into two groups: experimental and control groups (16 students each). Research tools used in this study were Social Phobia Inventory (SPIN), Behavioral Activation/Behavioral Inhibition Scales (BIS/BIS) and Anxiety Sensitivity Inventory (ASI-R). Prior to commencement of the intervention, a pretest was performed on each group then, the experimental group was exposed to transdiagnostic intervention, while the control group received no intervention. At the end of the intervention, a post-test was administrated to each group. The result of covariance analysis showed that the unified transdiagnostic intervention decreased behavioral inhibition and anxiety sensitivity, and increased behavioral activity. With regards to effectiveness of unified transdiagnostic intervention on social anxiety symptoms, utilization of this therapeutic method is suggested to psychologists and advisors.